1. Field of the Invention
This invention relates to protective caps for covering electrical terminals and more particularly, to such caps which are reusable, encapsulate the electrical terminals and also provide easy access to the terminals for testing without the necessity of removing the cap from the terminal.
2. Description of the Prior Art
Terminal blocks are used in the telecommunications industry in a wide variety of applications. The terminal blocks may include a threaded binding post to which the telephone wire is connected by a combination of nuts and washers. One example of such blocks are the A-line series of blocks sold by assignee's Reliable Electric/Utility Products operating unit. Quite typically, the terminal block may also be mounted inside of a suitable housing such as a pedestal or an aerial terminal. It has been found that such binding post terminal block designs are susceptible to corrosion in humid or corrosive environments.
One solution to overcome this susceptibility of the binding posts is to cover the binding post with an insulating cap which includes therein an encapsulant. One example of such a cap is shown in U.S. Pat. No. 4,634,207 (hereinafter the '207 patent). Another example of such a cap is shown in U.S. Pat. No. 4,674,820 (hereinafter the '820 patent).
The '207 patent shows in FIG. 1 one embodiment such a cap and in FIGS. 2A and 2B alternate embodiments therefor. In the embodiment of FIG. 1, the force means which ensures that the encapsulant is maintained in compressive contact with the binding post and substantially encapsulates the post is an element which is independent of the first means which contains the encapsulant. In the alternate embodiments, the force means is inherent in the first means.
In the alternate embodiment of FIG. 2A of the '207 patent, the force means is a split retaining nut which is integral to the housing which contains the encapsulant. The split retaining nut has an internal threaded portion that is complementary with the threads of the binding post. The nut is split so that it can be pushed axially onto the binding post without threading it. The nut is internally threaded so that it can grip the binding post upon cessation of the pushing action. In the alternate embodiment of FIG. 2B of the '207 patent, the force means is a uniblock device that fits over the entire terminal block.
The '820 patent shows a reusable terminal cap which includes a slot which is designed to be self tearing by the wire connected to the binding post as the cap is inserted over the wire. Struts are used interior to the cap to rigidify the cap's integral neck portion. The struts include a threaded or irregular surfaces which interact with the threads on the binding post as the cap is pressed onto the post.
In none of the embodiments shown in either the '207 or '820 patents is it possible to easily test the connections to the binding post without completely removing the cap from the post.